Fruit and Vegetables

Walnut - Juglans regia


GeneralitŠ°


Plant of ancient origins, originating from the regions of south-western Asia. It is a very vigorous tree, which can even reach 30 meters in height. It has deciduous leaves, each leaf is composed of 5-7-9 leaflets with a smooth surface. In the same plant male and female flowers are present together, the male flowers appear first, which are generally found in the branches of a year, while the female ones grow at the apex of the new shoots. The fruit is a drupe, the edible part of which is found inside a woody shell, which is covered by a green fleshy husk that, when the fruit is ripe, blackens and peels off. The harvest of the fruits takes place in the months of October-November, as soon as the husk starts to come off, then the walnuts must be exposed to the sun for a period of 10-12 days for drying. The walnut prefers deep, fresh and well-drained soils, it fears water stagnation, which can favor the onset of rot at the roots, causing a general weakening of the plant, with damage also to the production of fruits. It resists well to the cold while preferring mild and not too humid climates. The ideal area is the hill with altitudes not exceeding 600-800 meters, cultivation in the plains is also very widespread, where most of the plants are destined for the production of the very precious wood.

Propagation



Normally the common walnut is propagated by seed, while for other selections grafting is practiced. The most used graft holders are the frank and the black walnut. The Franco is more used in Europe, it gives an excellent development to the plant but delays the putting on fruit. Black walnut is mostly used in the United States, which reduces the development of the plant and anticipates its use.
The sowing must be carried out in the autumn period, in the months of September, October.

Pruning



The form of farming is certainly the natural one, given the great development of the plant. When it comes to pruning, it is important to keep in mind that cuts heal poorly and can often cause various types of infections. Therefore large cuts are to be avoided, being limited to the thinning of the small disordered branches and possibly practicing pruning every year, to avoid having to intervene on the larger branches.

Composting



As with many other plants, fertilizing is also recommended for the walnut, possibly every one or two years, with mature manure or other organic-based fertilizers, supplementing them with complex chemical fertilizers based on nitrogen, phosphorus, potassium and microelements . In less fertile soils it is necessary to increase the dose and the frequency of interventions with nitrogen fertilizers.

The diseases


Animal parasites can cause different damage according to the organs they strike. The worm (Cydia pomonella) for example, seriously damages the fruit by feeding on the internal almond. Another harmful insect, above all for the plants used for the production of wood, is the Rodilegno which digs deep tunnels in the trunk.
The pathogens of fungal and bacterial origin are: "The anthracnose", which causes, in addition to the fruit drop, also a rapid defoliation of the plant, and the root and basal rot that occurs in the presence of excessive soil moisture, causing cancers and swellings at the roots and at the base of the trunk, bringing the plant even to death. It is generally used in prevention with copper-based products (Bordeaux mixture and oxychlorides).

Walnut: cultivation techniques



The walnut tree begins to produce fruit around the tenth year of age and, with the passage of time the production of nuts tends to increase until it reaches its maximum around the thirtieth year, remaining so for about ten years, to then go gradually decreasing. To obtain a nut plant that is healthy and vigorous, it is good to put it in a well-drained soil, fresh and deep, rich in nourishment. Soils that are too compact should be avoided and the best substrate should have a neutral or slightly acid ph.
The planting of these plants should be done in the autumn / winter season. During the first years of cultivation it is also possible to plant other varieties around the plant, although it must be taken into account that, for a more comfortable harvest, it is good to leave the soil free.
It is a plant that resists the winter climate but can be affected by late frosts, which can ruin the flowering. It can withstand summer temperatures close to 40 ° C.